The modern communications era has brought about a tremendous expansion of wireline and wireless networks. Computer networks, television networks, and telephony networks are experiencing an unprecedented technological expansion, fueled by consumer demand. Wireless and mobile networking technologies have addressed related consumer demands, while providing more flexibility and immediacy of information transfer.
Current and future networking technologies continue to facilitate ease of information transfer and convenience to users. In order to provide easier or faster information transfer and convenience, telecommunication industry service providers are developing improvements to existing networks. For example, the evolved universal mobile telecommunications system (UMTS) terrestrial radio access network (E-UTRAN) is currently being developed. The E-UTRAN, which is also known as Long Term Evolution (LTE) or 3.9G, is aimed at upgrading prior technologies by improving efficiency, lowering costs, improving services, making use of new spectrum opportunities, and providing better integration with other open standards.
One advantage of E-UTRAN which continues to be shared with other preceding telecommunication standards is the fact that users are enabled to access a network employing such standards while remaining mobile. Thus, for example, users having mobile terminals equipped to communicate in accordance with such standards may travel vast distances while maintaining communication with the network. By providing access to users while enabling user mobility, services may be provided to users while the users remain mobile. Multimedia broadcast multicast service (MBMS) is an example of a service that has been developed to provide interactive and/or streaming content to users in a mobile environment.
LTE MBMS may be supported both on a carrier dedicated to MBMS usage and on a shared carrier in which MBMS is multiplexed with unicast downlink traffic. In addition, there may be different transmission techniques for LTE MBMS including single-cell point-to-multipoint (PtM) mode and MBMS single frequency network (MBSFN). In single-cell PtM mode, it may be possible to deliver MBMS data via common downlink resources and enable link adaptation using dedicated uplink feedback signaling. Link adaptation typically involves matching of the modulation, coding and other signal and protocol parameters to conditions on the radio link. Accordingly, link adaptation may be useful in maintaining continuity of service for a mobile terminal that is moving between different serving cells.
Recently, several scenarios have been identified as priority scenarios for optimizing service continuity in LTE MBMS. In this regard, exemplary scenarios include maintaining service continuity between intra-frequency shared carrier MBSFN and shared carrier single-cell PtM in both directions, between inter-frequency dedicated MBSFN and shared carrier single-cell PtM in both directions, and between intra-frequency shared carrier single-cell PtM and shared carrier single-cell PtM. However, for example, when link adaptation is used in single-cell PtM, the transmission mode may be optimized for mobile terminals that are currently receiving a particular service. Accordingly, if the mobile terminals currently receiving the particular service are located in an area with relatively good radio conditions (e.g., near the transmitting base station), it may be likely that a particular transmission format (e.g., a higher modulation and coding scheme (MCS)) may be in use in order to improve radio efficiency. Thus, if a new mobile terminal enters an edge of the service area provided by the transmitting base station, the particular transmission format may not be conducive to maintaining continuity of service for the new mobile terminal. For example, the MCS may be too high for the new mobile terminal (which may experience poorer radio conditions due to being at the edge of the service area) to decode the service correctly. Accordingly, the new mobile terminal may experience an outage that may result in a service break, which could continue until the new mobile terminal receives an uplink feedback channel to send channel quality information (CQI) reports and hybrid automatic repeat-request (HARM) ACK/NAK messages. The problem described above may be especially noticeable in a situation in which a mobile terminal in an idle state moves from one cell to another.
In light of the issues discussed above, it may be desirable to provide a mechanism for improving service continuity, even for mobile terminals in the idle state. Accordingly, it may be desirable to develop a mechanism by which at least some of the problems described above may be addressed.